The present invention is directed to electrical contact springs, particularly to those used for establishing and maintaining electrical connections between circuit boards.
When transmitting signals from board to board in an electrical circuit, it is essential that the integrity of the signals be protected or shielded from interfering with each other through noise, etc. Additionally, the length of the signal circuit must be relatively short to avoid disturbances of signal integrity related to length of connector.
Prior art patents directed to electrical connectors include U.S. Pat. Nos. 4,161,346, 4,505,529 and 4,752,231.
U.S. Pat. No. 4,161,346 is directed to an electrical connector for interconnecting electrical circuits on two electronic circuit boards involving surface to surface contact between generally parallel surfaces. The patent discloses a connector element having a symmetrical, sinuous shape including a spring section for exerting a determined contact force and establishing the electrical connection. In addition, the connecting element is provided with a separate shorting beam into connector opposed ends and the connecting element to provide a shorter electrical path and to act as a spring for retaining the contact element within its housing.
U.S. Pat. No. 4,505,529 relates to a connector for electrically interconnecting printed circuit boards in the form with three elongated beams extending between contact surfaces with the configuration of the contact element being such that it buckles under compression forces to provide spring forces.
U.S. Pat. No. 4,752,231 is directed to an electrical connector including a rigid insulating housing bolted between parallel circuit boards and having electrical connectors located within and positioned by the rigid housing for establishing electrical contact between the circuit boards. The connectors themselves are in the form of semi-elliptic springs having outwardly projecting tips for establishing contact with opposing portions of the circuit board.
U.S. Pat. No. 4,778,404 is of interest and is directed to a spring terminal having an intermediate spring portion form of spring sections joined at their adjacent ends to form a zig zag configuration. The terminal is held in a fixed position and is generally adapted for use in difficult environmental situations where mating connector members must be fully sealed.
A commercially available electrical connector includes telescoping, longitudinally connected spring loaded elements in the form of "pogo stick" for providing spring-biased connectors.
Each of the foregoing devices involves complex connector constructions including multiple components in several cases and complicated assembly techniques. Additionally, the block members used for holding and positioning the connectors also have intricate designs to accommodate assembly and functioning of the connectors. The complexities of design, assembly, and operation of these connectors are drawbacks in electronic circuit board devices having a multitude of connections and where available space is limited and are counterproductive as they increase opportunities for loss of signal integrity.